Fix debug adapter reconnection in attach mode with ReconnectableDebugController #1594

Copilot · 2025-10-03T08:48:41Z

Explored repository structure and understood the issue
Analyzed the debug adapter architecture
Identified the root cause: server stops on disconnect even in attach mode
Implemented initial fix attempt
Addressed code review feedback
Implemented Option B: ReconnectableDebugController
- Created new controller that properly disposes and recreates debug sessions
- Modified DefaultDebugService to raise Disconnected event
- Updated DebugBehavior to use reconnectable controller
- Properly handles session lifecycle with dispose/recreate pattern
Addressed additional code review feedback
- Simplified API: CreateDebugController() now directly returns reconnectable implementation
- Reverted DelayedConnectionChannel to original behavior (becomes invalid after use)
- Each new session creates fresh channel instances
- Properly dispose all IDisposable resources in DisposeSession method
- Made IDebugEventListener extend IDisposable for cleaner disposal pattern
Built and tested the solution
- All 32 debug protocol tests pass (27 original + 5 new)
- No compilation errors
- Clean architectural solution

Summary of Changes

The fix implements a clean architectural solution for debug adapter reconnection in attach mode:

1. ReconnectableDebugController (new)

A new controller implementation that supports reconnection by properly managing session lifecycle:

Disposes current debug session when client disconnects (terminate=false)
Creates a new session with fresh channel instances ready for the next connection
Uses event-driven approach to detect disconnections
Thread-safe session management with proper locking
Properly disposes all IDisposable resources including:
- DelayedConnectionChannel
- TcpEventCallbackChannel (via IDebugEventListener interface)
- ThreadManager

2. DefaultDebugService Disconnected Event

Added Disconnected event to allow controllers to react to disconnect operations:

Event raised before throwing StopServiceException
Includes DisconnectEventArgs with Terminate flag
Allows reconnectable controller to prepare for next session

3. IDebugEventListener Interface Enhancement

Modified IDebugEventListener to extend IDisposable:

Ensures all event listener implementations support proper disposal
Eliminates need for casting when disposing event listeners
Clean interface contract

4. TcpDebugServer Updates

CreateDebugController() now returns ReconnectableDebugController directly for all use cases

5. DelayedConnectionChannel (unchanged)

Reverted to original implementation where channel becomes invalid after connection loss - not reused across sessions

6. Enhanced Tests

Added tests for:

Disconnected event functionality
Event arguments validation
Total: 32 tests passing

How It Works

Client connects → ReconnectableDebugController creates new session with fresh channel
Client disconnects (terminate=false) → DefaultDebugService raises Disconnected event
ReconnectableDebugController receives event → disposes current session including all IDisposable resources → creates new session with new channel
Client reconnects → new session with fresh channel ready to accept connection

This approach is cleaner than keeping server threads alive indefinitely, properly manages resources with single-use channels and proper disposal, and supports unlimited reconnections.

Fixes #1593

Original prompt

This section details on the original issue you should resolve

<issue_title>Проблема с повторным подключением к процессу при помощи Debug Adapter</issue_title>
<issue_description>Опишите ошибку
При запуске скрипта с флагом -debug подключится к нему (attach) в режиме отладки при помощи VSCode.DebugAdapter можно только один раз. Если внутри VS Code отключиться (disconnect) от процесса отладки, а затем попытаться подключиться еще раз, то вернутся к отладке не получится: сам запущенный процесс oscript не завершает работу, но новый сеанс отладки (через attach) не инициализируется. Oscript не отвечает на указанном порту отладки

Возможно, это связано с флагами terminate и _attachmode в HandleDisconnect из DebugeeProcess.cs.
Вероятно нужно диспозить и пересоздавать контроллер при отключении адаптера

Воспроизведение ошибки

Code_xpy23zOiZr.mp4

Окружение

ОС: Windows 11

Версия: 2.0 rc-7
</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes #1593

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Co-authored-by: nixel2007 <[email protected]>

- Modified DefaultDebugService.Disconnect to not throw StopServiceException when terminate=false - Updated DelayedConnectionChannel to support reconnection by keeping listener alive - Modified DefaultMessageServer to continue on IOException/ObjectDisposedException instead of stopping - Added thread-safe reconnection logic with proper state reset Co-authored-by: nixel2007 <[email protected]>

nixel2007 · 2025-10-03T09:06:40Z

@copilot добавь тесты

- Added 3 unit tests for DefaultDebugService disconnect behavior - Tests verify that disconnect without terminate doesn't throw StopServiceException - Tests verify that disconnect with terminate throws StopServiceException - Tests verify breakpoints are cleared on disconnect - All 30 debug protocol tests pass Co-authored-by: nixel2007 <[email protected]>

Co-authored-by: nixel2007 <[email protected]>

Copilot · 2025-10-03T09:20:11Z

@copilot добавь тесты

Added tests in commit 74718db. The new ReconnectionTest class includes 3 unit tests that verify:

DefaultDebugService_ShouldNotStopOnDisconnectWithoutTerminate - Ensures disconnect without terminate flag doesn't throw StopServiceException
DefaultDebugService_ShouldStopOnDisconnectWithTerminate - Verifies disconnect with terminate flag throws StopServiceException
DefaultDebugService_ShouldClearBreakpointsOnDisconnect - Confirms breakpoints are properly cleared on disconnect

All 30 debug protocol tests pass (27 original + 3 new).

Bayselonarrend · 2025-10-03T09:23:41Z

@copilot С такой реализацией процессы оскрипта не будут завершаться никогда. Хотя, возможно, там бэкграунд тред, но все равно, это не оно. Чинить надо дропом одного DebugController и созданием другого

nixel2007 · 2025-10-03T09:24:53Z

@copilot отработай другие комментарии к пулл реквесту

Copilot · 2025-10-03T09:29:47Z

@copilot отработай другие комментарии к пулл реквесту

I don't see any other comments in the PR context provided. Could you please point me to the specific comments you'd like me to address? If there are inline code review comments, please share them so I can work on them.

Co-authored-by: nixel2007 <[email protected]>

Bayselonarrend · 2025-10-03T10:05:06Z

I don't see any other comments in the PR context provided. Could you please point me to the specific comments you'd like me to address? If there are inline code review comments, please share them so I can work on them.

@nixel2007 😭😭😭

nixel2007 · 2025-10-03T10:08:42Z

@copilot вот этот комментарий #1594 (comment)

Copilot · 2025-10-03T10:13:46Z

@copilot вот этот комментарий #1594 (comment)

You're right that the current approach isn't architecturally clean. However, a few clarifications:

The server thread is marked as IsBackground = true, so processes will terminate normally when the main thread exits
The proper fix (disposing and recreating DebugController) would require changes to how oscript manages the controller lifecycle in DebugBehavior.cs

I've reverted the changes to DefaultMessageServer.cs. To implement the reconnection properly, we have two options:

Option A (current approach - simpler but not ideal):

Keep the thread-safe reconnection logic in DelayedConnectionChannel
Let DefaultDebugService.Disconnect not throw when terminate=false
Server thread stays alive but it's a background thread

Option B (cleaner but more invasive):

Implement a new ReconnectableDebugController that can dispose/recreate the message server
Modify DebugBehavior to handle controller recreation
Properly dispose and recreate resources on each reconnection

Which approach would you prefer? Option B is cleaner but requires more extensive changes.

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@Bayselonarrend

Per feedback from @Bayselonarrend, reverted the changes to DefaultMessageServer that kept the server thread running indefinitely on connection loss. The current implementation still supports reconnection through DelayedConnectionChannel's thread-safe reconnection logic and DefaultDebugService not throwing StopServiceException on disconnect without terminate. Co-authored-by: nixel2007 <[email protected]>

nixel2007 · 2025-10-03T11:22:47Z

@copilot делай вариант B.

Implemented a cleaner architectural solution per code review feedback: - Created ReconnectableDebugController that properly disposes and recreates debug sessions - Modified DefaultDebugService to raise Disconnected event instead of just throwing - Updated TcpDebugServer to provide CreateReconnectableDebugController method - Modified DebugBehavior to use reconnectable controller - Added 2 new tests for Disconnected event functionality (total: 32 tests passing) The controller now handles reconnection by: 1. Listening for Disconnected events from DefaultDebugService 2. When disconnect happens without terminate flag, disposing current session 3. Creating a new session ready for the next connection 4. All resources properly disposed and recreated between sessions Co-authored-by: nixel2007 <[email protected]>

Copilot · 2025-10-03T11:37:20Z

@copilot делай вариант B.

Implemented Option B in commit 2a24f95.

Created ReconnectableDebugController that properly handles reconnection by:

Disposing and recreating debug sessions on disconnect (when terminate=false)
Using event-driven approach via new Disconnected event in DefaultDebugService
Thread-safe session management with proper resource cleanup
Updated DebugBehavior to use the reconnectable controller

All 32 debug protocol tests pass, including 2 new tests for the Disconnected event functionality.

coderabbitai · 2025-10-03T12:43:18Z

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sonar-openbsl-ru-qa-bot · 2025-10-03T12:44:32Z

Quality Gate passed

Issues

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Project ID: OneScript

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sonar-openbsl-ru-qa-bot · 2025-10-03T12:44:42Z

Quality Gate passed

Issues

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Project ID: OneScript

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EvilBeaver · 2025-10-04T18:30:42Z

src/oscript/DebugBehavior.cs

            var tcpDebugServer = new TcpDebugServer(_port);

-            DebugController = tcpDebugServer.CreateDebugController();
+            DebugController = tcpDebugServer.CreateReconnectableDebugController();


Не нужен отдельный метод. Пусть конкретная реализация выбирается внутри CreateDebugController

Fixed in commit addressing the feedback. CreateDebugController() now directly returns ReconnectableDebugController - removed the separate CreateReconnectableDebugController() method.

EvilBeaver · 2025-10-04T18:32:52Z

src/OneScript.DebugServices/Internal/DelayedConnectionChannel.cs

+                // Reset state if previous connection was lost
+                if (_reconciled && _connectedChannel?.Connected == false)
+                {
+                    ResetConnection();


Я бы предпочел, чтобы при потере связи канал Channel становился бы недействительным навсегда и инстанс повторно не использовался бы

Fixed in same commit. Reverted DelayedConnectionChannel to original implementation - the channel becomes invalid after connection loss and is never reused. ReconnectableDebugController now creates a fresh channel instance for each new session.

nixel2007 · 2025-10-04T19:39:04Z

@copilot обработай замечания к коду. Используй mcp playwright для получения комментариев

…onChannel Per code review feedback: 1. Removed CreateReconnectableDebugController() method - CreateDebugController() now returns ReconnectableDebugController directly 2. Reverted DelayedConnectionChannel to original implementation - channel becomes invalid after connection loss and is not reused 3. ReconnectableDebugController creates new channel instances for each session All 32 tests still passing. Co-authored-by: nixel2007 <[email protected]>

sonar-openbsl-ru-qa-bot · 2025-10-05T09:08:26Z

Quality Gate passed

Issues

Measures

Project ID: OneScript

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sonar-openbsl-ru-qa-bot · 2025-10-05T09:09:25Z

Quality Gate passed

Issues

Measures

Project ID: OneScript

View in SonarQube

Bayselonarrend · 2025-10-27T07:09:23Z

@EvilBeaver, есть возможность глянуть? Copilot вроде дописал правки по замечаниям

EvilBeaver · 2025-10-28T11:14:25Z

src/OneScript.DebugServices/ReconnectableDebugController.cs

+            _server?.Stop();
+            _threadManager?.Dispose();
+
+            // Don't dispose the channel or callback service, let them be garbage collected


@copilot ⬆️

The comment was misleading. Fixed in latest commit - the channel now properly calls Dispose() instead of just being set to null. DelayedConnectionChannel implements ICommunicationChannel which extends IDisposable, so it should be disposed to release resources properly.

Но это не так. Где вызов Dispose для Disposable-объектов, которым ниже присваивается null?

@copilot ответь на комментарий EvilBeaver

You're correct. Fixed in latest commit - added Dispose() call for _callbackService which implements IDisposable (it's a TcpEventCallbackChannel that wraps the communication channel).

Removed misleading comment and added proper disposal of DelayedConnectionChannel. The channel implements IDisposable and should be disposed rather than just set to null. Co-authored-by: nixel2007 <[email protected]>

Added disposal of _callbackService which implements IDisposable. TcpEventCallbackChannel wraps an ICommunicationChannel and needs to be disposed to properly release the underlying channel resources. Co-authored-by: nixel2007 <[email protected]>

EvilBeaver · 2025-10-30T08:40:11Z

src/OneScript.DebugServices/ReconnectableDebugController.cs

            _server?.Stop();
            _threadManager?.Dispose();
+            _channel?.Dispose();
+            (_callbackService as IDisposable)?.Dispose();


Зачем нужен этот каст? Сделай, пожалуйста, интерфейс _callbackService наследником IDisposable, если это не так

@copilot посмотри комментарий

Fixed in latest commit. Made IDebugEventListener extend IDisposable, so the cast is no longer needed. All implementations now properly implement disposal pattern.

Modified IDebugEventListener interface to extend IDisposable, eliminating the need for casting in ReconnectableDebugController. This ensures all event listeners implement proper disposal pattern. - Updated IDebugEventListener to inherit from IDisposable - Removed explicit IDisposable from TcpEventCallbackChannel (now inherited from interface) - Added empty Dispose() method to OscriptDebugEventsListener (no resources to dispose) - Removed cast in ReconnectableDebugController.DisposeSession() All 32 tests pass. Co-authored-by: nixel2007 <[email protected]>

Initial plan

4c5da55

Copilot AI assigned Copilot and nixel2007 Oct 3, 2025

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Copilot AI and others added 2 commits October 3, 2025 08:54

Initial exploration of debug adapter reconnection issue

9f47c0f

Co-authored-by: nixel2007 <[email protected]>

Copilot AI changed the title ~~[WIP] Проблема с повторным подключением к процессу при помощи Debug Adapter~~ Fix debug adapter reconnection in attach mode Oct 3, 2025

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Remove accidental opm.ospx file

33ce069

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Addressing PR comments

0e44c9b

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Copilot AI changed the title ~~Fix debug adapter reconnection in attach mode~~ Partial fix for debug adapter reconnection in attach mode Oct 3, 2025

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Copilot AI changed the title ~~Partial fix for debug adapter reconnection in attach mode~~ Fix debug adapter reconnection in attach mode with ReconnectableDebugController Oct 3, 2025

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Properly dispose channel in DisposeSession

c9b35d4

Removed misleading comment and added proper disposal of DelayedConnectionChannel. The channel implements IDisposable and should be disposed rather than just set to null. Co-authored-by: nixel2007 <[email protected]>

Copilot finished work on behalf of nixel2007 October 28, 2025 12:23

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Fix debug adapter reconnection in attach mode with ReconnectableDebugController #1594

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Fix debug adapter reconnection in attach mode with ReconnectableDebugController #1594

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Summary of Changes

1. ReconnectableDebugController (new)

2. DefaultDebugService Disconnected Event

3. IDebugEventListener Interface Enhancement

4. TcpDebugServer Updates

5. DelayedConnectionChannel (unchanged)

6. Enhanced Tests

How It Works

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